Abstract
Background. More than half of persons living with HIV (PLWH) in the United States are
insufficiently engaged in HIV primary care and not taking antiretroviral therapy (ART),
mainly African Americans/Blacks and Hispanics. In the proposed project, a potent and
innovative research methodology, the multiphase optimization strategy (MOST), will be
employed to develop a highly efficacious, efficient, scalable, and cost-effective
intervention to increase engagement along the HIV care continuum. Whereas
randomized controlled trials are valuable for evaluating the efficacy of multi-component
interventions as a package, they are not designed to evaluate which specific
components contribute to efficacy. MOST, a pioneering, engineering-inspired
framework, addresses this problem through highly efficient randomized
experimentation to assess the performance of individual intervention components and
their interactions. We propose to use MOST to engineer an intervention to increase
engagement along the HIV care continuum for African American/Black and Hispanic
PLWH not well engaged in care and not taking ART. Further, the intervention will be
optimized for cost-effectiveness. A similar set of multi-level factors impede both HIV
care and ART initiation for African American/Black and Hispanic PLWH, primary
among them individual- (e.g., substance use, distrust, fear), social- (e.g., stigma), and
structural-level barriers (e.g., difficulties accessing ancillary services). Guided by a
multi-level social cognitive theory, the study will evaluate five distinct intervention
components (i.e., Motivational Interviewing counseling sessions, pre-adherence
preparation, support groups, peer mentorship, and patient navigation), each designed
to address a specific barrier to HIV care and ART initiation. These components are
well-grounded in the empirical literature and were found acceptable, feasible, and
promising with respect to efficacy in a preliminary study.
Methods/design. Study aims are: 1) using a highly efficient fractional factorial
experimental design, identify which of five intervention components contribute
meaningfully to improvement in HIV viral suppression, and secondary outcomes of
ART adherence and engagement in HIV primary care; 2) identify mediators and
moderators of intervention component efficacy; and 3) using a mathematical modeling
approach, build the most cost-effective and efficient intervention package from the
efficacious components. A heterogeneous sample of African American/Black and
Hispanic PLWH (with respect to age, substance use, and sexual minority status) will be
recruited with a proven hybrid sampling method using targeted sampling in community
settings and peer recruitment (N=512).
Discussion. This is the first study to apply the MOST framework in the field of HIV
prevention and treatment. This innovative study will produce an HIV care continuum
intervention for the nation's most vulnerable PLWH, optimized for cost-effectiveness,
and with exceptional levels of efficacy, efficiency, and scalability.